﻿/* Copyright (C) 2008 - 2011 by John Cronin
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:

 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

using System;
using System.Collections.Generic;
using System.Text;

namespace tysos
{
    class MemoryAllocator
    {
        static ulong heap_start = 0;
        static ulong heap_end = 0;
        internal static ulong cur_end_of_heap = 0;

        public static void DefineHeap(ulong start, ulong end)
        {
            heap_start = start;
            heap_end = end;
            cur_end_of_heap = heap_start;
        }

        [ABI.MethodAlias("gcmalloc")]
        [ABI.AlwaysCompile]
        public static ulong Alloc(ulong size)
        {
            if (size > (heap_end - cur_end_of_heap))
            {
                Program.arch.BootInfoOutput.Write("Out of memory!");
                ABI.OtherOperations.Halt();
            }
            cur_end_of_heap += size;
            return cur_end_of_heap - size;
        }
    }
}
